SEM-EDXRA studies of precipitates which clogged a water-tube filter

Abstract

Light microscopic, submicroscopic and XRD (X-ray diffraction) analyses were done of precipitates which had clogged a water-tube filter. Several zones, mostly consisting of amorphous and poorly crystalline materials, could be distinguished. SEM-EDXRA (scanning electron microscopy — energy dispersive X-ray analysis) indicated that sulphur, copper, iron and zinc were usually represented and that calcium was less common. Light microscopy and XRD indicated the presence of calcite and gypsum. Corrosion of copper filter segments could be demonstrated by flakes which peeled off, small fragments adjacent to the segments, and a jagged appearance of the edges. A little sulphur was found at the edges of the filter segments together with copper. More sulphur was present in the flakes which, together with copper, formed covellite according to XRD analyses. Rather massive precipitates could be deposited on the disintegrating flakes. Precipitates of younger zones were usually less massive and exhibited a variety of forms.